Polar regions

The concentration of methane in the atmosphere is rising, according to measurements made by the New Zealand National Institute of Water and Atmospheric Research (Niwa) at its Baring Head Station near Wellington.

Methane (CH4) is a greenhouse gas whose affect on climate is 21 times stronger than Carbon Dioxide (CO2) and is the second most important contributor to global warming behind carbon dioxide. It is produced naturally mainly by biological breakdown of organic substances in oxygen-deficient conditions, such as the digestive system of ruminant animals and the decay of plant material in swamps or landfills. It is also prevalent in fossil fuels such as coal, oil, and natural gas (which is mainly methane).

Strange Climate Bedfellows: Black Carbon Bill Unites Boxer, Kerry, Inhofe

Arctic Sea Ice extent is still shrinking according to NASA and the National Snow and Ice Data Center. The thickness of Arctic ice is also reducing. Over the 2009 winter the Arctic had the fifth lowest maximum ice extent on record. The six lowest maximum events since satellite monitoring began in 1979 have all occurred in the past six years (2004-2009).

In early April 2009 the Wilkins Ice Bridge connecting Latady and Charcot Island on the Antarctic Peninsula collapsed. The disintegration of this ice bridge will allow the further disintegration of the Wilkins ice shelf. A large part of the Wilkins Ice Shelf disintegrated in February 2008.

Scientists meeting in Copenhagen have said that sea level rise this century may exceed a metre, far beyond the estimates of the International Panel on Climate Change released two years ago which projected a sea level rise of 18 - 59 centimeters to 2100.

"Unless we undertake urgent and significant mitigation actions, the climate could cross a threshold during the 21st century committing the world to a sea level rise of metres", said Dr John Church, lead speaker in the sea level session and from the Centre for Australian Weather and Climate Research in Hobart.

Arctic summer sea ice is headed towards rapid disintegration as early as 2013, a century ahead of the International Panel on Climate Change (IPCC) projections, according to 'the Big Melt' (PDF), a new review of recent scientific literature on climate change produced by www.carbonequity.info. We have gone past the tipping point for Arctic sea ice and now we watch the disintegration of the Greenland and the West Antarctic ice sheets which will result in catastrophic changes in sea level of 5 metres or more in the next 100 years.